$\left(\frac{1}{5}x^2+7\right)\left(\frac{1}{5}x^2-7\right)$

$\int_{10}^{30}\left(\frac{1}{20}\right)e^{-\frac{x}{20}}dx$

$-n^2+100n+1$

$-2x-16x+25$

$3\cdot2^{3y}=7\cdot3^{3x-2}$

$\frac{4x\left(x-2\right)^2}{8x^2\left(x-2\right)}$

$\frac{sin\:x}{cos\:x}+\frac{cos\:x}{sin\:x}=\frac{1}{cos\:x\:sin\:x}$